Comparative Study on Satellite-Based SAR Image Representation for Detection of Landslides and Sediment Disasters Caused by Rainfall

Comparative study on satellite-based SAR (Synthetic Aperture Radar) image representation for detection of landslides and sediment disasters caused by rainfall is conducted. There are many SAR image representation methods depending on the purposes. In this study, the most appropriate image representation method for detection of landslide and sediment disaster by rainfall is proposed. Through experiment with Sentinel-1/SAR, it is found that the RGB ratio which is VV/VH/ratio channel assignment is the most appropriate method rather than SAR urban, Enhanced Visualization, VV polarization, VH Polarization. From the scattering mechanism at the land surface (interaction between electromagnetic wave and the land surface), it seems the RGB ratio is the most appropriate method. It is confirmed by the other method which compare between before and after the disaster occurred of SAR imagery data. Therefore, it is validated the proposed method with the actual land slide and sediment disaster, which was occurred at Karatsu, Kyushu in Japan on 10 July 2023.